Distillate petroleum product and method of treating same



Patented Mar. 13, 1934 UNITED STATES PATENT- orr'lcr.

DISTILLATE PETROLEUM ,PRODUCT AND METHOD OF TREATING SAME James B.Rather, Brooklyn, Orland M. Reifl,

Jackson Heights, and Leslie C. Beard,

Brooklyn, N. Y., assignors to Socony-Vacuum Corporation, New York, N.Y., a corporation of New York No Drawing. Application April 23,1929,

Serial No. 357.603

1 Claims. (01. 44-9) our co-pending applications Serial No. 315,914

filed October 29, 1928, Serial No. 151,005, filed November 26, 1926 andSerial No. 165,546 filed February 3, 1927.

It is well known that during storage, the lighter refined petroleumdistillates, notably gasoline and kerosene, frequently become discoloredand develop a quantity of gummy material and an objectionable odor, as aresult, itis generally believed, of atmospheric oxidation. And it isknown that cracked gasoline will generally accumulate a gummy materialduring comparatively short periods of storage, particularly in the glassbowls of visible service pumps.

This discoloration and odor developed in gasoline and kerosene areobjectionable to consumers and distributors of these products and thepresence of gummy material in gasoline causes such undesirable effects,when used ln internal combustion engines, as sticking of the valve stemsand excessive carbon formation.

. In accordance with this invention, however,

'the development ofthese undesirable character istics indistillatepetroleum products may be readily prevented or materiallydelayed and any without appreciably increasing the cost of productionthereof.

One of the-objects, therefore, of thisqinvention, is to provide amethod'of and means for preventing or materially delaying the develop-.

vment of discoloration, objectionable odor and the formation of gummymaterial in distillate petroleum products.

Another object of the invention is to provide a method of and means forremoving objectionable color developed in distillate petroleum productsand for preventing initial and recurrent discoloration thereof.

Another object of the invention is to provide agents 'or compoundseflective both as decolorizers and color stabilizers of distillatepetroleum products and alsoeflective to prevent or matelly delay theformation of gum and objectionable odor therein.

Another object of the invention is to provide amethod and means of thecharacter referred to that will not appreciably increase the cost ofproduction of distillate petroleum products.

Other objects of the invention will be apparent from the followingdescription.

We have discovered that certain of the hy- 0 droxy compounds, such asthe hydroxy benzenes and particularly the trihydroxy benzenes areeffective as decolorizers and stabilizers with respect to color, gumformation and odor of distillate petroleum products of A. P. I. gravityhigher than 37. Of the trihydroxy benzenes, pyrogallol is preferablyemployed because, in addition to its eflectiveness in decolorization andcolor and odor stabilization, it is probably the most effective of thetrihydroxy benzenes in prem venting or delaying the formation oi. gum inpetroleum distillates.

The method employed preferably comprises the thorough mixing of arelatively minute amount of the agent or compound, such as pyrogallol,T5

with the distillate to be treated, although it will be understood thatthe distillate may be percolated through a mass of the agent orcompound, if desired. Preferably, however, the pyrogallol is firstdissolved in a suitable solvent which is The resulting solution is thenadded to the distillate to be treated in the desired proportion. By thismethod the pyrogallol is distributed throughoutand dissolved in thedistillate more readily than if it'were added directly thereto.

It has been found that as little as one part 99 by weight of pyrogallolto approximately 75,000 parts of distillate is an effective proportionfor decolorizing and for preventing the development of objectionable,color, odor and the formation of gum. Somewhat larger proportions maybe used, if desired, but the absorption of too large a quantity. of theagent or compound may result in discoloration due to the compoundimparting its own color to the distillate.

In most instances, however, the distillate will gallol solution is thenadded gradually to the distillate to be treated. and preferably in suchquantities that the ratio of the amount of pyrogallol to the distillatewill be approximately one part by weight of pyrogallol to 75,000 partsof distillate. After the pyrogallol and the distillate have beenthoroughly mixed, the resulting solution is conducted into a clean, drytank, and allowed to stand until the reaction of the pyrogallol with thedistillate is complete. At ordinary temperatures, this usually, requiresabout 24 hours, but at higher temperatures, the time required may besomewhat less. During this treatment the distillate should preferable bekept out of contact with water otherwise the agent or compound may bedissolved in the water and possibly result in the return of some degreeof discoloration.

Tests have shown that a distillate petroleum product having an initialcolor of 9 Saybolt Chromometer, when treated with as little as one partof pyrogallol to 75,000 parts of the distillate and allowed to stand foronly two hours, had a color of +18 Saybolt, thus showing an improvementin color of 27- points Saybolt.

The gum forming tendency of distillate petroleum products, such asgasoline, for example, may be efiectually measured by the evaporation ofthe gasoline in a copper cup according to the United States Bureau ofMines Method 530.1, Technical Paper 3233. Tests in accordance with thismethod have shown that with commercial samples of. unrefined gasolinedis tillate, the amount of gum formed by the evaporation of the gasolinein a copper cup prior to. treatment with pyrogallol amounted to 288millegrams, whereas after treatment with as little as .one part ofpyrogallol dissolved in mono parts of the gasoline, only 7 millcgramswere formed.

The foregoing treatment has been found most satisfactory and eflectivein thedecolorization and stabilization of distillate petroleum prodnetsof A. P. I. gravity higher than 37 with respect to color, gum formationand odor, and is particularly advantageous because it does notappreciably increase-the cost of production or the handling chargesthereof. I

While we have thus specifically described our invention, variousmodifications thereof may suggest themselves to those skilled in theart, and it is therefore our intention that the invention. be limitedonly by the scope of the appended claims.

Having thus described our invention, what we claim and desire to secureby Letters'Patent is:

1. A low boiling normally light colored dis tillate petroleum product ofthe class of gasoline or kerosene which normally tends to be comediscolored during storage, having added thereto a polyhydroxy-benzeneefi'ective to, and

in quantity suflicient to, substantially retard spontaneousdiscoloration of the product.

2. The method of stabilizing the characteristics of a low boilingnormally light colored distillate petroleum product of the class ofgasoline or kerosene that normally tends to become discolored duringstorage, which comprises adding thereto prior to substantial spontaneousdiscoloration a small quantity of a polyhydroxybenzene sufilcientsubstantially to retard selfgenerated discoloration of the product.'

3. A low boiling normally light colored distillate petroleum product ofthe class of gasoline or kerosene which normally tends to bee comediscolored during storage, having added thereto a trihydroxy-benzene inquantity sumcient substantially to retard spontaneous discoloration oithe product.

4. The method of stabilizing the characteristics of a low boilingnormally light colored distillate petroleum product of the class ofgasoline or kerosene that normally tends to become discolored duringstorage, which comprises adding thereto prior to substantial spontaneousdiscoloration a small quantity of a trihydroxy-benzene-sumcientsubstantially to retard discoloration of the product. v

5. The method of stabilizing the characteristics of a low boilingnormally light colored distillate petroleum product of the class ofgasoline or kerosene that normally tends to become discolored duringstorage, which comprises adding thereto prior to substantial spontaneousdiscoloration a small quantity oi? pyrogallol sufiicient substantiallyto retard spontaneous color formation.

6. The method of stabilizing the characteristics of a low boilingnormally light colored distillate petroleum product of the class ofgasoline or kerosene that normally tends to become discolored duringstorage, which comprises add-' 7. n'substantially water white-color lowboil= gallol in amount suflicient substantially to retard the atoresaiddiscoloration and insumcient in amount to impart substantial color tothe product.

ORLANDQ M. mrsnm e. nnAnn, Ja.

